Fuel systems



1951 G. w. HARRY 2,996,190

FUEL SYSTEMS Filed Sept. 3, 1957 FUEL 701v IN VEN TOR.

fwd)? yam nited States Patent Ofiice 2,996,190 Patented Aug. 15, 1961 2,996,190 FUEL SYSDEMS Gordon W. Harry, Flushing, Mich, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Sept. 3, 1957, Ser. No. 681,681 lClaim. (Cl. 210-436) The present invention relates to a fuel system and more particularly to a fuel system vapor separator for use with internal combustion engines.

High ambient temperatures have been known for some time to cause vapor lock in engine fuel systems preventing proper operation of engines served by such systems. Fuels of high volatility have aggravated this situation and the same is true in cases of air conditioning apparatus installed under the engine hoods. Operation of vehicles in mountainous areas has also contributed to the troublesome condition which prevents the proper feeding of liquid fuel to the engine.

Filtering devices have been incorporated as separate elements in fuel systems for performing the filtering function and an advantage obviously resides in placing such filter elements in the systems in such a way as to eliminate the use of extra parts.

An object of the present invention is to provide an improved vapor separator in a fuel system which prevents vapor lock in serving an internal combustion engine. Another object of the invention is to provide a fuel system vapor separator in which a fuel filter element is advantageously incorporated to minimize complexity of construction.

A feature of the invention is a vapor separator adapted to be installed on the discharge side of a fuel pump and vented in such a way as to be capable in returning vapor to the source of fuel supply. Another feature of the invention is a vapor separator adapted to be vented to a fuel supply source and incorporating a fuel filter in its structure.

These and other important features of the invention will now be described in detail in the specification and then pointed out more particularly in the appended claim.

In the drawings:

FIG. 1 is a diagrammatic representation of a fuel system in which a vapor separator is incorporated, this system being an embodiment of the present invention; and

FIG. 2 is a sectional view looking in the direction of the arrows 22 in FIG. 1. L

In FIG. 1 the system is shown as including a fuel supply or fuel tank 10, a fuel pump 12, a vapor separator generally indicated at 14 and a carburetor 16 as conventionally used on internal combustion engines. It will be appreciated that insofar as the present invention is concerned the carburetor may be considered to be a part of the engine and that a carburetor may not necessarily be involved. A conduit 18 is shown connecting the fuel tank 10 to the pump 12. Another conduit 20 connects the pump to a main body 22 of the separator 14. This conduit 20 communicates with a horizontal passage 24 formed in the body 22. This passage connects with a central vertical passage 26 leading up to the interior of an inverted glass bowl 28. The latter is held to the main body 22 by a conventional bail arrangement 30. The bottom rim of the inverted cup 28 fits snugly to the top of the body 22 with a sealing washer 32 interposed to prevent leakage. A central tube 34 extends vertically with its upper end in direct communication with the upper interior of the bowl 28. The lower end of this tube 34 is supported by a lower bottom portion of the main body 22 and this portion defines a horizontal port 36 as well as a restricted passage 38 giving communication between the tube 34 and the port 36. The latter is connected to the fuel tank 10 by a return or vent line 40.

An annular filter-element 42 is enclosed within the inverted cup 28 and is so made as to surround the tube 34 and the vertical passage 26 and lie transverse to the path of fluid flow. The interior and exterior margins of the filter element 42 connect in abutting relation with the main body 22 constraining fluid flow through the separator 14 so that the fluid path passes through the filter element and into an annular chamber 44 formed in the body 22. A second vertical passage 46 is formed in the body 22 giving communication between the annular chamber 44 and a conduit 48 which is connected as a feed line to the engine or carburetor 16.

In vehicle use the conduits 18 and 20, as well as the fuel pump 12, may be subjected to sufliciently elevated temperatures to cause vaporization of the fuel passing through the system. As a result, the fuel pump 12 becomes wholly or partially disabled and incapable of performing its function as desired; but with the present device any vapor formed in the system will rise to the top interior zone of the inverted cup 28 and, being under pressure because of the action of the fuel pump 12 or subsequent flowing liquid will flow downwardly through the tube 34 and be conducted to the fuel tank 10. Any air present in the fuel tank will be vented through a gasoline tank filler cap, for example, as customary, and any fuel vapor returned to the tank will be condensed because of the relatively low temperatures to which the fuel tank is subjected as compared with the fuel system under the engine hood.

When all vapor has been ejected from the system, the inverted bowl 28 will be filled with liquid fuel. As a consequence, some liquid fuel as limited by the restricted passage 38 will be circulated back to the fuel tank 10. This has the advantage of lowering the temperature of the fuel in the entire system and diminishing the possibility of vapor lock occurring. As the venting is continuous, vapor lock is no longer a problem.

The vertical disposition of the tube 34 is particularly advantageous because it permits the opportunity for providing a convenient and advantageous structure involving the use of the bowl 28 and the filter element 42.

Iclairn:

A vapor separator for use in a fuel system for an internal combustion engine comprising a fuel reservoir and a liquid pump, said vapor separator comprising a main body and an inverted bowl cooperating to define a vapor separating chamber, means defining a restricted vent passage leading from the upper portion of said vapor separating chamber downwardly through the bottom of said main body and adapted to be connected to said reservoir, said main body having inlet and outlet passages coaxial with said vent passage and communicating with said separating chamber, an annular filter element in said bowl traversing a flow path from said inlet passage to said outlet passage, an inlet port in said main body adapted to connect said reservoir and pump to said inlet passage and an outlet port in Said main body adapted to connect said outlet passage to said engine for providing the latter with filtered liquid fluid from which vapor has been removed by way of said restricted vent passage.

References Cited in the file of this patent UNITED STATES PATENTS Stewart Mar. 24, 1903 

